Cavity solitons are optical pulses that propagate indefinitely in nonlinear resonators. They are attracting attention, both for their many potential applications and their connection to other fields of science. Cavity solitons differ from laser dissipative solitons in that they are coherently driven. So far the focus has been on driving Kerr solitons externally, at their carrier frequency, in which case a single stable localized solution exists for fixed parameters. Here we experimentally demonstrate Kerr cavity solitons driving at twice their carrier frequency, using an all-fibre optical parametric oscillator. In that configuration, called parametric driving, two backgroundless solitons of opposite phase may coexist. We harness this multiplicity to generate a string of random bits, thereby extending the pool of applications of Kerr cavity solitons to random number generators and Ising machines. Our results are in excellent agreement with a seminal amplitude equation, highlighting connections to hydrodynamic and mechanical systems, among others.

腔孤子是在非线性谐振器中无限传播的光脉冲。它们吸引了人们的注意力，无论是因为它们的许多潜在应用还是它们与其他科学领域的联系。腔孤子与激光耗散孤子的不同之处在于它们是相干驱动的。到目前为止，重点一直是在外部以载波频率驱动克尔孤子，在这种情况下，对于固定参数存在单一稳定的局部解。在这里，我们使用全光纤光学参量振荡器通过实验证明以两倍载波频率驱动的克尔腔孤子。在这种称为参数驱动的配置中，两个反相的无背景孤子可以共存。我们利用这种多重性来生成一串随机位，从而将克尔腔孤子的应用范围扩展到随机数发生器和伊辛机。我们的结果与一个开创性的振幅方程非常一致，突出了与流体动力和机械系统等的联系。